China Factory Suppliers of DIN 6921 Black Oxide Carbon Steel Bolts Grade 8.8, 10.9, 12.9
Production parameter
| thread specification d | M12 | M16 | M20 | (M22) | M24 | (M27) | M30 | M36 | |
| P | pitch | 1.75 | 2 | 2.5 | 2.5 | 3 | 3 | 3.5 | 4 |
| b | L≤100mm | 25 | 31 | 36 | 38 | 41 | 44 | 49 | 56 |
| L＞100mm | 32 | 38 | 43 | 45 | 48 | 51 | 56 | 63 | |
| c | Max | 0.8 | 0.8 | 0.8 | 0.8 | 0.8 | 0.8 | 0.8 | 0.8 |
| Min | 0.4 | 0.4 | 0.4 | 0.4 | 0.4 | 0.4 | 0.4 | 0.4 | |
| da | Max | 14.7 | 18.7 | 23.24 | 25.24 | 27.64 | 31.24 | 34.24 | 41 |
| ds | Max | 12.7 | 16.7 | 20.84 | 22.84 | 24.84 | 27.84 | 30.84 | 37 |
| Min | 11.3 | 15.3 | 19.16 | 21.16 | 23.16 | 26.16 | 29.16 | 35 | |
| dw | Min | 19.2 | 24.9 | 31.4 | 33.3 | 38 | 42.8 | 46.5 | 55.9 |
| e | Min | 22.78 | 29.56 | 37.29 | 39.55 | 45.2 | 50.85 | 55.37 | 66.44 |
| k | nominal | 7.5 | 10 | 12.5 | 14 | 15 | 17 | 18.7 | 22.5 |
| Max | 7.95 | 10.75 | 13.4 | 14.9 | 15.9 | 17.9 | 19.75 | 23.55 | |
| Min | 7.05 | 9.25 | 11.6 | 13.1 | 14.1 | 16.1 | 17.65 | 21.45 | |
| k1 | Min | 4.9 | 6.5 | 8.1 | 9.2 | 9.9 | 11.3 | 12.4 | 15 |
| r | Min | 0.6 | 0.6 | 0.8 | 0.8 | 1 | 1.2 | 1.2 | 1.5 |
| s | Max | 21 | 27 | 34 | 36 | 41 | 46 | 50 | 60 |
| Min | 20.16 | 26.16 | 33 | 35 | 40 | 45 | 49 | 58.8 | |
| Thread b | - | - | - | - | - | - | - | - | |
Production description
Steel structural bolts are high-strength bolts and also a type of standard component. Good fastening performance, used in steel structures and engineering to enhance the fastening effect. On general steel structures, the required steel structural bolts are grade 8.8 or above, as well as grade 10.9 and grade 12.9, all of which are high-strength steel structural bolts.
Steel structural bolts are mainly used in steel structural engineering to connect the connection points of steel structural steel plates.
Steel structural bolts are divided into torsion shear high-strength bolts and large hexagonal high-strength bolts. Large hexagonal high-strength bolts belong to the high-strength grade of ordinary screws, while torsion shear high-strength bolts are an improved type of large hexagonal high-strength bolts for better construction.
Matters needing attention in construction
The construction of the steel structure bolt must first tighten and then tighten, the first tightening steel structure bolt needs to use the impact type electric wrench or the torque adjustable electric wrench, and the final tightening steel structure bolt has the strict request, the torque-shear type electric wrench must be used for the final tightening of the torsion-shear type steel structure bolt, and the torque type electric wrench must be used for the final tightening of the torsion-shear type steel structure bolt. Large hexagonal steel structural bolts consisting of one bolt, one nut, and two washers. Torsional shear type steel structure bolt, by a bolt, a nut, steel structure big hexagon bolt a washer composition.